Sealing-off machine



Octe 5 1926; 1,601,902

- c. Bol.

SALING-OFF MACHINE:

Filed Feb. 14; 1924 2 sheets-sheet 1 Corneli S Bol.

Patented oa. 5, 1,926.

'l UNITED STATES 1,601,902 PATENT OFFICE.v

CORNELIS BOL, OF EINDHOVENVNETHERLANDS. ASSIGNOR T GENERALl LELEC'IRIGA COMPANY, A CORPORATION OF NEW YORK.

BEALING-OFF MACHINE.

Application-tiled February 14,1924, Serial No. 692,853, and in Holland Iarch 19, v1923.

This invention relates .to apparatus for sealing off a number of parallel glass tubes and more particularly the exhaust tubes ofy 'said apparatus is preferably so designed thatgas can be supplied to the burners during the-reciprocating movement of the frame. Each burner is preferably so arranged that it directs several radial flames on to the circumference' of the glass tube.

If theinvention is to be applied to simultaneou-sly se'alin olli` a number of exhaust tubesof bulbs or' electric lamps or other hollow vessels to be exhausted, a vertically reciprocatable table may, according to the invention, be provided having attached thereto a burner for each exhaust'tube and ,having apertures to receiveI the said exhaust tubes so that as the said table moves upwards after the sealing-olf operation, the bulbs alone are carried along and the exhaust tubes remain behind.

If the burners are to be used also during the reciprocatin movement of the table, gas 'may be supplied to the burners through a vhollow shaft or hollow shafts to which the frame is attached.

The apparatus,l according to the invention for simultaneously sealing olf a number of exhaust tubes can be applied' to various known ump installations. It can be used for sealing off vacuum lamps as well as gasilled lamps.

The bulbs to be exhausted are connected to the vacuum conduit by the exhaust tubes which may in known manner be fused to glass tubes, communicating with the vacuum conduit or which may also in known manner, be placed in tubes of elastic material such as ruber which tightly surround the exhaust tu es.

The advantagesof the invention are enhanced by the use of special devices for holding and making a tempora hermetic seal around the exhausttubes. e said devices are hereinafter referred t9 as locking devices and comprise -a tubular body of elastic material, devices for clamping both ends thereof and a device for pressing the free middle part of the elastic body against thc wall of the exhaust tube by means of a liquid or a gaseous medium under pressure. 1n this case said locking devices are located below the apertures in the vertically reciprocatable table in which the exhaust tubes of the bulbs are inserted.

The advantages offered by such an arrangement are very considerable as the exhaust tubes can 'be laced in the locking devlces without any iiiiculty so that it is possible to insert a number of lamps in the i pump installation within a very short time,

whilst also the sealing-olf operation subsclquent to exhaust can be carried on very 'quickly by using the device according to the invention.

The accompanying drawingillustratesby way of example a pump installation embodying the invention.

Figure 1 is a front view of the installation and Figure 2 is a vertical cross-section with a partial side view of the installation as shown in Figure 1.

`As shown in the-drawing, various parts of the 'device are secured to two plates l and 17 rest-ing on legs 18 and 19. The plates 1 and v17 have fastened thereto an angle-iron 2 which supports bent hangers 3 and 43 on which are placed the locking devices which will be ldescribed hereinafter.

Two vertical shafts 4 and 5 are slid'able vertically in brackets 6, 7 and 8, 9 lwhich are attached respectively to the plates 1 and 17. The said vertical shafts carry the sealing-ofi' device which will be described in detail here.

inafter.

Each shaft 4 and 5 is provided with a toothed' rack 10 which engages a toothed w'heel 11 keyed to a horizontal shaft 12which is rotatably supported in the lates 1 and 17 and carries a hand wheel 13 rlgidly mounted thereon. By operating the hand wheel 13 a sealing-olf ca 20 can be raised or lowered relatively to t e locking devices. A counterweight 15 which is 'attached to the hand wheel 13 by means of a belt 14 secured thereto by a stud 16 insures that the locking device remains stationaryin any position to which it has been raised or lowered.

The hangers 3 and 43 support vacuum con- 2'1 and 2g which are closed at both ends and connected by a tube 23. The conduits 21 and 22 carry a number of vertical tubes 24 and 25 at the ends of which are disposed the locking devices 26 and 27 which serve to' make a temporary hermetic seal around the exhaust tubes. v

In the apparatus illustrated there are six vertical tubes for each vacuum conduit. It will be clear, however, that a greater 'or smaller number of vertical tubes can be used, if desired.

One of the locking devices 26 will now be described in detail by reference to Figure 2. A tube 28 of elastic material such as rubber is slid over the upper end of the tube 24 and is hermetically clamped at both ends. Its lower end is held between the lower end of a metal tube 29 and a conical portion of thetube 24 and its upper end is bent around the upper end of the tube 29 to which it is clamped by a small metal cap which is drawn downward by ,springs 30 and 31 having their lowerends secured to a ring 32 rigidly attached to the tube 24.

A rod 35 of small diameter is vertically slidable in a small tube 34 within the tube 24. The said rod`35 which lis resiliently sup-ported by a coiled spring 33 is flattened at the upper end where it carries a small ring 36 thus allowing-.an exhuast tube 42 to rest on it.

In order that the tube 28 shall not be heated to an objectionably high temperature some suitable cooling liquid such as water is caused to circulate through a conduit 37 around the said metal cap.

Asshown. in Figure 1 said conduit is led alongall the/locking devices. The cooling liquidis supplied from a tube 38 through a. cock 39 and the conduit 37 is opened out at the other end into two tubes 40 and 41 of small diameter thus allowing the water to fiow into the enlarged upper end of an outlet tube 84, such end being for example of glass.

The middle portion of the tube 28 (Figure 2) 'can freely movel relatively to the wall of the metal tube 29 so that the tube 28 by the supply of a gaseous or a liquid medium under pressure can be hermetically pressed against the exhaust tube `42.

In order to cause the tube 28 to fall back out .of engagement with the exhaust tube 42 it is advisable to connect the space between the tube 28 and the metal tubel 29 with a vacuum. j l' A conduit 45 extends Vat one end through v the wall of the tube 29 and is at the other end connected to a horizontal tube 47 which is secured to a support 48.

The locking devices 27 are connected to thel tube 47 in a similar wa by conduits 46. From the tube-47 is. lcd7 downward a tube 49 which communicates with a three- Way cock 50. The latter connects the tube 49 either witha conduit 51 for air under pressure or with a preliminary vacuum conduit 53 and thus by turning the cock 50 the space around the elastic tube 28 can be connected alternately with a vacuum and with air under pressure.

The horizontal vacuum tube 21 has connected thereto a tube 55 which by means of a cock 56 can be connected to a vacuum conduit 57.

The vacuum conduit 57 can be connected in known manner either to a preliminary vacuum or to a high vacuum. The apparatus may also be provided with a yfeed tube for some gas such as`a-rgon or nitrogen with which the bulbs after exhaustion may be filled, if desired.- It will be observed that not all of the aforesaid parts are shown in the drawing. y

The sealing-olf cap will now be described in detail.

The vertical shafts 4 and 5 carry at their upper end the two cross beams 2O and 44 respectively (Figure 1) to which plates 64 -and 65 (Figure l) and a table 62 are secured by bolts 60 and 61 (Figure 2). The space between the plates 64 vand 65 is filled with a heat insulating material 66 such as asbestos so that the locking devices 26- and 27 are protected against high temperature when in the vicinity of the burners. A number of apertures 67 and 68 in the plates 64 and 65 corresponding to the number of locking devices allow for the passage of the exhaust tubes. Opposite the said apertures are openings in the table 62 to hold the bulbs 63.

It may `be observed that the exhaust tubes 42 and the bulbs 63 are shown in the drawing in the position which they occupy after the bulbs have been exhausted and sealed off. l

In the vicinity of each set of apertures, radial burners 69 and 70 for heating the exhaust tubes are disposed. A mixture of gas and air is forced to said burners through tubes 71 and 72 which are supported on the plate 65 and are connected to channels 73 in the shafts 4 and 5.

At the lower end of said channels, tubes tube 77 which in turn is connected with a' shut-olii' cock 78 through which a mixture of gas and air can be vsupplied from an air tube 80 and a gas tubev 81.

It may beobserved thatjthe locking devices 26 and 27 are disposed between pro' provided with a.

tectin walls 82 and 83 heat insulating material.

iis

In order' to heat the bulbs during exhaustion any suitable known vdevice may be employed.A Such a device is not shown in the drawing as its constructiondces not fall within the scope of the invention.

The operation'of the deviceaccording to the invention as shown in the drawing will now be briefiy described.

At the beginning of the operation thc sealing-off cap is in its lowest position. The

. bulbs to be exhausted are then placed by .the springs 33.

the operator with their exhaust tubes in the corresponding apertures of the sealing-off cap. In doing so the lower ends of the exhaust tubes are seated on the upper ends of the small rods 34 within the locking devices. The weight of the bulbs slightly compresses By turning the cock 50 air under pressure is then forced into the locking devices so that a temporary hermetic seal is obtained around the exhaust tubes, whereupon the exhaust operation can be started. To that end the cock 56 is placed in the open position so that the tubes 21 and 22 are connected to a vacuum tube 57. The latter may be first 'connected rwith a preliminary vacuum and then with a high vacuum. During exhaustion the lamps are prefer-v ably heated to the maximum temperature allowable by means not shown on the drawings. vIf desired, the bulbs can be provided with a suitable gaseous filling. When a suiiciently high vacuum is obtained or when the bulbs are filled with the desired gas the gas cock is opened and the gas fiames near the burners 69 and 70 are ignited. The glass of the exhaust tubes is thereby softened -near the bottom of the bulbs and thus the exhaust tubes are sealed off. When the operator sees that the sealing-0H operation has sufliciently .proceeded he raises the sealingoff cap, the exhaust tubes being thus left in the locking devices. By thatI time the cock 56 is closed and at the same time the cock 50 is turned to the position in which the locking devices are connected with the preliminary vacuum so that the walls of the elastic tubes 28 fall back out of engagement with the exhaust tubes. rlihereupon the exhaust tubes can freely move in the locking devices and are raised by the springs which were compressed by the weight of the bulbs thus allowingl the easy removalI of the exhaust tubes from the locking devices. The finished bulbs are withdrawn from the sealing-ofil cap and fresh bulbs inserted whereupon `the cycle of operations is repeated. i

Vhat I claim as new and desire to secure 1. In a device of the character lescribed, the combination of a plurality ,of exhaust heads for holding exhaust tubes side by side, a table mounted to overhang said heads and `by Letters Patent of the United States, is

to reciprocate along said tubes, said table being heat insulated to adapt it to form the bottom of .an oven,V and having openings through which said tubes may extend above the table, means on said table for fusing said tubes near the top of said table, and manually operable means for at will reciprocating said table.

2. In a device of the character described, the combination of a reciprocating heat insulated table having transverse slots, means for at will raising and lowering said table, exhaust heads mounted underneath said table to register with the inner ends of Y CORNELIS BOL. 

